6CARDIOLOGY – QUESTIONS1.15 Theme: The sick newborn <strong>in</strong>fantA Pulmonary atresiaB Tetralogy of FallotC Coarctation of the aortaD Hypoplastic left heart syndromeE Transposition of the great arteriesF Interrupted aortic archG Obstructed total anomalous pulmonary venous connectionH Critical aortic stenosisI Ebste<strong>in</strong> anomalyChoose the most likely diagnosis from the histories and f<strong>in</strong>d<strong>in</strong>gs detailedbelow. Each option may be used once, more than once, or not at all. 1. A 6-day-old baby presents cyanosed, with a severe metabolic acidosis.On exam<strong>in</strong>ation, there is a large liver but no audible heartmurmur. ECG and chest X-ray were both reported to be normal. 2. A breathless baby with a cleft palate, absent left brachial andfemoral pulses, and a normal ECG. 3. A very unwell baby, with a loud heart murmur, a superior axis on theECG, and reduced pulmonary vascular mark<strong>in</strong>gs on the chest X-ray.
CARDIOLOGY – ANSWERS 7MT–F Answers1.1 Muscular ventricular septal defects (VSDs): DVentricular septal defects are the most common form of congenital heartdisease, compris<strong>in</strong>g 30% of the total number of cases. Muscular VSDs occur<strong>in</strong> the muscular part of the ventricular septum. Subacute bacterialendocarditis (SBE) prophylaxis is no longer <strong>in</strong>dicated, now only be<strong>in</strong>grequired <strong>in</strong> rare and specific cases. The pulmonary resistance is high atbirth, and hence there is little shunt between the two ventricles andtherefore no audible murmur <strong>in</strong> the first 24 hours. Only 25% of VSDsrequire cardiac surgery, and this is usually performed when the child is 3–5months of age. Very few patients have <strong>in</strong>terventional catheter closure,usually for smaller defects and at a later age. The conduction tissue islocated <strong>in</strong>feriorly <strong>in</strong> a perimembranous septal defect, which means thatsurgeons need to avoid that area when sutur<strong>in</strong>g a patch <strong>in</strong> place to closethe defect. If the VSD is large, patients present with symptoms of heartfailure after the first week of life and at that age have a right ventricularheave, a soft systolic murmur accompanied by an apical mid-diastolicmurmur, and a loud pulmonary second heart sound on exam<strong>in</strong>ation.1.2 Scimitar syndrome: B DScimitar syndrome is a form of anomalous pulmonary venous dra<strong>in</strong>age <strong>in</strong>which the ve<strong>in</strong>s from the lower right lung dra<strong>in</strong> <strong>in</strong>to the <strong>in</strong>ferior vena cava.The right lung itself is hypoplastic, and there is an associated dextrocardiadue to the heart mov<strong>in</strong>g over to the right side of the chest, but withnormal situs. Situs is the orientation of the organs, situs solitus be<strong>in</strong>gnormal, and situs <strong>in</strong>versus be<strong>in</strong>g mirror image. The arterial supply to thelung is from branches of the descend<strong>in</strong>g aorta. The right upper lobepulmonary ve<strong>in</strong> dra<strong>in</strong><strong>in</strong>g <strong>in</strong>to the <strong>in</strong>ferior vena cava may be seen as avertical l<strong>in</strong>e on a chest X-ray and is known as the ‘scimitar sign’. There maybe an atrial septal defect, and children can suffer with recurrent chest<strong>in</strong>fections, which may require right lower lobectomy.1.3 Congenital heart disease on the first day of life: D EBabies present<strong>in</strong>g with left-to-right shunt will have no murmur or symptomson the first day of life, because the pulmonary vascular resistance has yet tofall. Similarly, any common mix<strong>in</strong>g disease, such as atrioventricular septaldefect, can present with severe cyanosis on the first day of life, with highpulmonary vascular resistance, before breathlessness and heart failuredevelop at 1 week of age or more. All the obstructed left heart lesions, such